1. Field of the Invention
This invention relates to a plate-making sheet for a stamp-making apparatus which makes a desired stamp by exposing a stamp body having a stamp surface made of ultraviolet-curing resin to ultraviolet rays via a mask of an ink ribbon printed with a stamp image, especially a plate-making sheet of this kind to be affixed to the back of the stamp, and a group of such plate-making sheets, as well as a printing apparatus which employs such plate-making sheets therefor.
2. Prior Art
Conventionally, a stamp-making apparatus of the above-mentioned kind has been proposed by Japanese Laid-Open Patent Publication (Kokai) No. 6-278350. The stamp-making apparatus includes a supply reel on which an ink ribbon used as a mask for exposure and a printing paper ribbon corresponding to the above-mentioned plate-making sheet are wound in a state laid one upon the other. The stamp-making apparatus has a printing block provided with a print head and a platen roller, and the ink ribbon and the printing paper ribbon are rolled out from the supply reel by the platen roller and fed to the print head, where printing is effected simultaneously on the ink ribbon and the printing paper ribbon. Thereafter, the ink ribbon is fed further to an exposure block, and the printing paper ribbon is discharged from the apparatus. From the printing paper ribbon, a stamp character label is peeled off for being affixed to the back of the stamp body exposed to ultraviolet rays.
In the conventional stamp-making apparatus, it is necessary to cut the printing paper ribbon discharged from the apparatus in accordance with the size of the back of the stamp body, so that a cutter is needed and a troublesome cutting work is required. Further, the printing paper ribbon and the ink ribbon wound in a state laid one upon the other around the supply reel makes the diameter of the supply reel very large, causing an undesirable increase in the size of a ribbon cartridge incorporating the supply reel. Conversely, if the diameter of the supply reel is set or restricted to a suitable size, it will cause the inconvenience that the printing paper ribbon and the ink ribbon wound therearound become short in length, and ribbon cartridges are required to be changed more frequently.